Reproducer for phonographs and the like



April 16, 1929.

C. H. DAVIS REPRODUCER FOR PHONOGRAPHS AND THE LIKE Filed March 31, 1926Patented Apr. 16, 1929.

UNITED STATES 1,709,391 PATENT OFF-ICE.

CLAUDE HUDSON DAVIS, Q]? MOSMAN, AUSTRALIA, ASSIGNOR TO THE RESONATORLIMITED,OF SYDNEY, .NEW SOUTH WALES, A COMPANY OF NEW SOUTH WALES.

nnraonncnaron rnoivoeaarris AND THE LIKE.

Application filed March 31, 1926, Serial No. 98,780, and in AustraliaMay 4, 1925.

The invention is for use with phonograph disc records and theusualmechanism for rotating same and provides a reproducer of simpleconstruction, having acoustical qualities of high perfection.

According hereto a light sonorous chest (herein termed amplifier) madeof thin sheet material bent or moulded into shape preferably conical, iscarried at its larger end within a ring which hasa holder for anordinary. phonograph needle. The ring has hinge connection to a spindleturning on a vertical axis whereby freedom of movement in vertical andhorizontal planes is permitted as the needle follows the sound groove inthe record.

Referring to the drawing Fig. 1 is a front elevation partly in tion.

Fig. 2 is a side sectional elevation. 4 Fig. 3 is a cross sectionalelevation of a detail. j

Fig. 4 is a front elevation partly in section.

Fig. 5 isa plan of a detail. Fig. 6 is a plan of Fig. 1. First referringmore particularly to Figs.

1,2 and 3. The conical amplifier 1, of thin Wood is carried-at itslarger end within a channel, 2, in the cane ring 3, being held inposition by a series of cork or wooden bridge pieces, 4, located atintervals around thefiring and glued thereto and to the amli er.

p The phonograph needle, 5, is' secured with in the socket, 6 of theneedle holder 7 by a set screw 8 the rear end of the needle holder 7being provided with a screw threaded tapered end to enable it to bescrewed into a wooden block 9 that is glued to the periphery of the ring3.

The reproducer 1s supported by means of a pillar 10 having a socket 19to receive a spindle 20 having a shoulder 21 and a jaw 4 22 to receive aspecially shaped bracket 23 which is provided with a jaw 24 wherein aportion of ring 3 may lie and be firmly secured by screws 25 that passthrough perforations 26 in the side members of the jaw 24 and thecorresponding holes in the ring 3. The bracket 23 is pivoted in the 'jaw22 by the pin 27 to provide freedom of movement in a vertical plane andto enable the reproducer to be swung over when it is desired to renewthe needle. Stops 28 on the curved extension 32 of the bracket contactwith the side-of the jaw 22 when the reproducer has been movedsufliciently to bring the preponderance of its Weight upon that side ofthe pivot 27. The position of the bracket 23 when the reproducer is inan inoperative-position is shown by dotted lines at Figure 4.

The lower end of the pillar 10 is provided with a key 11, screwedcentrally into the bottom end thereof, and projecting s'ufliciently toenable it to be passed through a central key-way 12 formed in a metalplate or disc 13 securely fastened to the upper horizontal member 14: ofthe cabinet 15 by screws 16, a recess 17 being cut in the mem ber 14 toreceive the key 11 and allow it to be turned therein. .Stops 18 areformed upon the under side of the plate 13 in order to limit themovement of the key, and with it the pillar 10, when it has beeninserted in the key way 12.

It has been found that the most suitable location for the pillar 10 issuch that when the reproducer is swung through an are 0 which passesthrough the pivot 29 the needle will traverse the arc (see dotted linesFig. 6) almost to the pivot 29.by which said disc record 30 is retainedin position upon'the driven platform 31.

Hitherto the various methods adopted for reproducing sound inphonographs have all followed the principle of forming a connectionbetween the needle or stylusand the centre or a point near the centreofa diaphragm and, in many cases, a tone arm has been provided for thepurpose of conveying sound, produced by the vibrations of the diaphragm,transmitted thereto from the needle or stylus, to an amplifying horn orchamber. My invention differs from these methods in that the vibrationsare first transmitted from the phonograph needle to a ring and fromthence to an amplifier. Without departing from the spirit'thereof myinvention may be carried into effect in a variety of ways and a numberofdifferent materials may be used.

. Although the amplifier has been shown conical, and that shape ispreferred, experiments have proved that it need not be confined to thatparticular shape for instance it spherical or other hollow shapes. Itshould also be noted that whilst the method herein described andillustrated in the drawings for securing the peripheral edge of theamplifier to give excellent results of other methods for example, pensedwith there are a number that could be employed, the bridge pieces couldbe disand the convex face of the amplifier glued to the adjacent edge ofthe ring around the channel and a length of cane packed and gluedbetween the concave face of the amplifier and the adjacent side of thechannel.

I claim 1. An acoustic device including an amplifier, a ring having achannel which receives the peripheral edge of said amplifier, and aneedle holder carried by the peripheral edge of the ring and constructedto receive a needle for transmitting sound vibrations to the ring.

2. An acoustic device comprising a conical amplifier, a ring having achannel wherein the peripheral edge of the amplifier may freely lie,bridge pieces interposed between the amplifier and the adjacent edge ofthe channel of the ring such bridge pieces being glued to the amplifierand to the ring, and a needle holder secured to the ring and constructedto receive a needle whereby Within the channel has been found andcontructed to receive sound vibrations are transmitted from a discrecord.

3. An acoustic device comprising a conical amplifier, a ring having achannel which receives the peripheral edge of the amplifier, a needleholder secured to the ring a needle whereby sound vibrations aretransmitted from a disc record, and means for mounting so that thereproducer and the ring may rise and fall and also move in an arc acrossthe face of the disc record.

at. An acoustic device as claimed in claim 3, wherein the means formounting the ring consists of a recessed pillar, a spindle ha ving abifurcated projection swivelled therein, and an attaching bracketpivoted in the upper end of the spindle and attaelual to the ring,substantially as and for the purposes set forth.

5. An acoustic device including in combiuation a ring having a groove.on its inner circumference, an amplifier the outer periphery whcreofbeing located in said groove, means for mounting the outer periphery ofthe amplifier within the groove, and a needle holder secured to andconnected solely to said ring.

In Witness whereof I have signed this specification.

CLAUDE HUDSON DAVIS.

